An easy, durable way to add on to your existing compost bin. A. 2-INCH AIR FLOW GAP: Creates the perfect balance of natural elements to achieve fast and relatively smell-free composting. B. VINYL LEGS: Durable and resistant to rot and decay. C. NATURAL CEDAR: Water-resistant, supports organic gardening D. TOOL-FREE ASSEMBLY: Boards simply slide into the legs' grooves; assembles in less than 15 minutes. 1 – 2x4 KIT + 1 – 2X4 EXPANSION KIT Add on to your original compost bin to create the combination that best fits your lifestyle. 1 – 2x4 KIT + 1 – 4X4 EXPANSION KIT Combine two different sizes of compost bins together. For this combination, you must begin with a standard 2x4 bin and add on the 4x4 expansion kit. 1 – 2x4 KIT + 2 – 2X4 EXPANSION KIT Boards are removeable for easier access to compost.